[Quantal,SRU,PULL] fix XPS12 Cypress PS/2 trackpad

Bug reference:

	https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1103594
	Cypress Trackpad mis-detected as "PS/2 Cypress Trackpad" on XPS 12

[IMPACT]

Due to a firmware change in the Cypress PS/2 trackpad, the driver fails
to properly detect the trackpad in the Dell XPS12 and possibly other models,
leaving the trackpad dysfunctional.

This patch -- a trivial backport from upstream -- fixes the detection glitch
in the driver.  The patch was cherry-picked into Raring.

[TESTCASE]

The patch was deployed as SAUCE in Raring some weeks ago, as well as in the
Sputnik kernel PPA for Q and P.  It has been verified to fix the problem in
all three.

[Regression Potential]

Low potential for regression: The change will only affect Cypress PS/2
trackpads (the problem and fix occur only after the trackpad has already been
detected as a Cypress), and it has been reasonably widely tested on Cypress
pads with the older firmware via the Sputnik PPA.

Thanks,

 -Kamal

-------- >8 ----------------------------------------------------

The following changes since commit e102e4b9a51ed048b4a6e0b642a51463347739e2:

  UBUNTU: SAUCE: Bluetooth: Add support for 105b:e065 (2013-03-28 12:02:08 -0600)

are available in the git repository at:

  git://kernel.ubuntu.com/kamal/ubuntu-quantal.git cypress-xps12-sru1103594

for you to fetch changes up to a98edde7c575c44f362445367478da212a32f5fd:

  Input: cypress_ps2 - fix trackpadi found in Dell XPS12 (2013-04-03 13:29:41 -0700)

----------------------------------------------------------------
Kamal Mostafa (1):
      Input: cypress_ps2 - fix trackpadi found in Dell XPS12

 drivers/input/mouse/cypress_ps2.c |   19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

On 04/03/2013 02:06 PM, Kamal Mostafa wrote:
> git://kernel.ubuntu.com/kamal/ubuntu-quantal.git cypress-xps12-sru1103594

On Wed, Apr 03, 2013 at 02:06:21PM -0700, Kamal Mostafa wrote:
> Bug reference:
> 
> 	https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1103594
> 	Cypress Trackpad mis-detected as "PS/2 Cypress Trackpad" on XPS 12
> 
> [IMPACT]
> 
> Due to a firmware change in the Cypress PS/2 trackpad, the driver fails
> to properly detect the trackpad in the Dell XPS12 and possibly other models,
> leaving the trackpad dysfunctional.
> 
> This patch -- a trivial backport from upstream -- fixes the detection glitch
> in the driver.  The patch was cherry-picked into Raring.
> 
> [TESTCASE]
> 
> The patch was deployed as SAUCE in Raring some weeks ago, as well as in the
> Sputnik kernel PPA for Q and P.  It has been verified to fix the problem in
> all three.
> 
> [Regression Potential]
> 
> Low potential for regression: The change will only affect Cypress PS/2
> trackpads (the problem and fix occur only after the trackpad has already been
> detected as a Cypress), and it has been reasonably widely tested on Cypress
> pads with the older firmware via the Sputnik PPA.
> 
> Thanks,
> 
>  -Kamal

Looks to be self contained and specific to a version of one piece of
hardware.  Appears reasonably well tested.

Acked-by: Andy Whitcroft <apw@canonical.com>

-apw